The overall aim of the Indiana Gene Array Core is to collaborate with INIA investigators to understand the differences in gene expression in the extended amygdala that are involved in the development of excessive drinking. Our hypothesis is that both innate differences in gene expression and differences in response to alcohol and to paradigms involving exposure to alcohol or its withdrawal (gene-environment interactions) contribute to the development of excessive alcohol drinking. The Indiana Gene Array Core will focus on the use of Affymetrix microarrays to measure gene expression in selected regions of rat brains and in Drosophila mutants after various treatments;primary collaborators will be McBride (U01), Ryabinin (U01) and Davis (U01). These studies build upon our work during the initial grant period;carrying out the follow-up studies in the same laboratory (with many of the same technical personnel) will reduce technical variations and allow more powerful metaanalyses. We will work with investigators on experimental design, extract and purify RNA from rat brain tissues provided by the collaborating investigators, carry out all of the quality control and biochemistry involved in GeneChip experiments, extract the data and assist with analyses and bioinformatics. This core will be housed in the Center for Medical Genomics, directed by the PI, which has all of the necessary equipment and carries out a high volume of Affymetrix GeneChip experiments with a focus on quality control. We will extend our services to include quantitative RT-PCR confirmation of key findings from the microarrays that we process, and will offer such services to other members of INIA. We will also provide members of INIA analyses of cis-acting elements that contribute to the differences in gene expression detected in the microarray experiments;we have developed model-based techniques that do not require prior knowledge of binding sites. This Core will provide high quality data in an efficient and economical way. We already have strong relatioinships with the users, which will benefit the overall project.